Embodiments of the present invention generally relate to power transfer systems and, more particularly, to contactless power transfer systems.
Power transfer systems are employed for transmitting power from one object to another. Based on a method of transmitting power, the power transfer systems can be classified into power transfer systems using physical connections between a transmitter and a receiver for transmitting power and contactless power transfer systems in which there is no physical connection between the transmitter and the receiver.
The contactless power transfer systems employ various methods for transmitting power wirelessly. One such approach is an inductive coupling system that includes a transmitter coil and a receiver coil in which both are inductively coupled to a respective transformer winding and transmit power based on inductive coupling.
In an alternative approach, a resonator based contactless power transfer system is used that includes a three coil system for transmitting power over a distance. The three coils include a transmitter coil, a receiver coil and a resonator for enhancing a resonance coupling between the transmitter coil and the receiver coil. Typically, efficiency and power transfer capability of the contactless power transfer system depends on distances between the transmitter coil and the receiver coil and the physical alignment between the transmitter coil and the receiver coil. The efficiency and the power transfer capability of the three coil system decreases gradually as the distance between the transmitter coil and the receiver coil is increased. In addition, small misalignment between the transmitter coil and the receiver coil results in significant decrease in the efficiency and power transfer capabilities of the three coil systems. Therefore, a more efficient contactless power transfer system with lesser sensitivity to misalignment is desirable in certain applications such as EV charging, for example.
Hence, there is a need for an improved system to address the aforementioned issues.